Foot-operated, hand-released parking brake



April 9, 1968 J. R. KIRK Re- 26,372

FOOT-OPERATED, HAND-RELEASED PARKING BRAKE] Original Filed Feb. 13, 19652 Sheets-Sheet x Aprll 9, 1968 J. R, KIRK FOOT-OPERATED, HANDRELEASEDPARKING BRAKE 2 Sheets-Sheet 2' Original Filed Feb. 13, 1963 UnitedStates Patent O 26,372 FOT-OPERATED, HAND-RELEASED PARKING BRAKE JosephR. Kirk, Jackson, Mich., assignor to Atwood Vacuum Machine Company,Rockford, lll., a corporation of Illinois Original No. 3,194,085, datedJuly 13, 1965, Ser. No. 258,352, Feb. 13, 1963. Application for reissueFeb. 23, 1967, Ser. No. 626,644

9 Claims. (Cl. 74-540) Matter enclosed in heavy brackets appears in theoriginal patent but forms no part of this reissue specification; matterprinted in italics indicates the additions made by reissue.

ABSTRACT F THE DISCLOSURE A push and pull rod operable horizontally by ahandle conveniently arranged relative to the driver beneath theinstrument board has a right angle benl inner end portion slia'able in ahorizontal slot in a supporting bracket and also slidable in anintersecting cam slot provided in a pawl that is pivoted to the bracketand is arranged to engage teeth in the periphery of a segmental shapedratchet to hold the parking brake in braking position unless the pawl ismoved to a retracted position by an outward pull on the aforesaidhandle. The ratchet is pivoted to the same bracket with the pawl and isoperable by a foot-pedal. A spring normally holds the rod in its brakerelease position, and there is another spring that normally holds thepawl in engagement with the teeth of the ratchet except when the rod ispulled to the rear, holding the pawl retracted by cam action. Then theparking brake can be used the same as a regular brake, engaged only solong as the operator keeps the foot-pedal depressed.

This invention relates to parking brakes for motor vehicles and is moreparticularly concerned with one that is foot-operated and has a handrelease.

Most foot-operated parking brakes have been equipped with some form offoot-operated release, which have many objections, the principal onesbeing awkwardness and uncertainty of operation. The driver also couldnot be certain that the parking brake was fully released, and, if thebrake was left applied to even a small extent, the resulting decreasedgasoline mileage and increased wear on the brake lining were bothserious but inevitable results with that general design. With theseearlier constructions there was also the necessity for a signal light orWarning buzzer to indicate to the driver if the parking brake was leftapplied when the ignition was turned on to start the engine. Of course,that meant additional expense and introduced the possibility of thesignal being out of order at some time. Therefore, it is the principalobject of my invention to provide an improved handoperated release whichis simpler and more dependable, besides being easily accessible for handrelease from the drivers scat, and which when pulled out gives completeassurance of full release, thereby avoiding the objections mentioned.

In the parking brake of my invention a pawl that is spring-pressedtoward engagement with a segmental ratchet oscillatable with the parkingbrake pedal in the application of the brake to keep the brake applied isarranged to be retracted against the action of its spring by pulling outa handle on a rod mounted for reciprocation at about instrument boardlevel, a right angle horizontal front end portion on the rod beingguided in a pair of registering horizontal guide slots provided in asupporting bracket on which the pedal is mounted for oscillation, thepaw] having a generally triangular cam slot provided Re. 26,372 ReissuedApr. 9, 1968 ice therein through the wide front end portion of which therod extends to cam the pawl to retracted position in the rearwardmovement of the rod for instant and complete release of the brake, therod having a spring serving normally to hold the right angle end thereofin the forward end of the horizontal guide slots so that the pawl canoscillare freely with respect to it and cooperates properly with thesegmental ratchet to lock the pedal in braking position.

The invention is illustrated in the accompanying drawings, in which-FIGS. l and 2 are a side view and top view, respectively of a parkingbrake assembly made in accordance with my invention, and

FIG. 3 is a view similar to FIG. l showing a modied or alternativeconstruction utilizing a single tension spring between the pawl andpedal.

Similar reference numerals are applied to corresponding parts throughoutthese views.

Referring first to FIGS. 1 and 2, the reference numeral 4 designates asheet metal supporting bracket of generally triangular form that isadapted to be bolted at its forward end 5 to the dash D by means ofstuds 6 and also to be secured at its rear end 7 to the bottom of theinstrument board I by means of a bolt entered in the slot 8. A plate 9is riveted to the bracket 4 by means of the upset opposite ends of apivot pin 10, and the parking brake pedal 11 is mounted between thebracket 4 and plate 9 on this pin for oscillatory movement, the pedal 11having a pad 12 mounted on the rear end thereof providing a wide surfacefor the driver to apply pressure usually with his left foot when theparking brake is to be applied, thereby swinging the pedal 11 in aclockwise direction as viewed in FIG. l, the forwardly reaching arm 13on the pedal causing the forwardly reaching arm 14 that is provided as apart of the segmental-shaped ratchet 15 that is pivoted with the pedal11 on pin 10 to be turned through the same angularily in a clockwisedirection as the pedal 11. A pawl 16 pivoled at 17 with respect tobracket 4 is urged under tension of spring 18 toward engagement with theratchet teeth 19 to lock the ratchet in adjusted position and keep theparking brake set, the arm 14 being pivotally connected as at 20 to aclevis 21 onto which the operated end of the parking brake cable C isattached in keyhole slot 22. The spring 18 has its one end attached to alug 23 on the plate 9 while the other end is hooked in the wide frontend of a generally triangular-shaped cam slot 24 provided in the pawl16.

The substantially horizontal pull rod 25 is reciprocable in a bearinggrommet 26 mounted in a hole 27 in the rear end of bracket 4 and has acoiled compression spring 28 caged between the front of the grommet 26and the back of two diametrically opposed eyebrow projections 29 swedgedfrom the rod 25, so that when the rod 25 is pulled to the rear by meansof the T-shaped handle 30 provided on the rear end of the rod the spring28 is compressed and tends to return the rod and handle to its initialposition. A substantially horizontal right angle bent end portion 31 ofrod 25 is guided in substantially horizontal guide slots 32 and 33provided in registering relation in bracket 4 and plate 9 and normallyis held by action of spring 28 engaged in the front end of these guideslots, the latter serving also positively to limit the rearward pull ofrod 25 by engagement of the end portion 31 in the rear ends of theseguide slots. The end portion 31 of rod 25 extends through the wide endof the generally triangular cam slot 24 in pawl 16 and, due to thedownward inclination from a horizontal of the upper side of cam slot 24with respect to guide slots 32 and 33 in the brake holding position ofthe pawl 16, the pawl is cammed upwardly to released position when therod 25 is pulled to the rear. Hence, if the parking brake has beenapplied by depression of pedal 11, the brake is released immediatelyupon retraction of the pawl 16 by means of rod 25. Eyebrow projection 34swedged from the extremity of the end portion 31 alongside the outwardlyswedged portion of bracket 4 delining slot 32 serves to prevent lateraldisplacement of the rod end 31 from slots 32 and 33. Plate 9 issimilarly swedged outwardly as indicated at 36 in FIG. 2 to define slot33, and these two swedged portions 3S and 36 afford broad enough bearingsurfaces for sliding engagement thereon of the rod end 31 so that theoperation of the rod 25 back and forth in the guide slots 32 and 33 issmooth and easy, and wear on the parts is reduced to a minimum. A rubberbumper 37 is mounted on an inclined axis on a lug 38 on plate 9 and isarranged to be struck by the back edge of the pedal 11 when the brake isreleased and the cable permits the pedal 11 to return to its normalposition as shown in FIG. 1, thereby silencing the operation andabsorbing shock.

In operation, when the parking brake is to `be applied, the driverdepresses the pedal 11, thereby pulling upwardly on the cable C attachedat 22 on clevis 21, the segmental-.shaped ratchet 15 being turnedthrough nearly in a clockwise direction in that `amount of movement ofpedal 11 and being locked securely by means of the spring-pressed pawl16 so as to hold the parking `brake in set condition. Under theseconditions the right angle forward end portion 31 of rod 2S. beingaccurately located with respect to the pawl by virtue of its engagementin guide slots 32 and 33 and being at the outset disposed in the widefront end portion of the triangular cam slot 24 in no way interfereswith the freedom of oscillation of pawl 16 as the pawl rides over theratchet teeth 19 to the point of its locking position, namely, wherethere is no further movement of pedal 11 in setting the parking brake.The instant the driver pulls rearwardly on handle 30. the straight linemovement of the right angle end portion 31 of .rod 25 is accuratelydetermined by guide slots 32 and 33 on a horizontal line at an acuteangle relative to the top of cam slot 24, so that the pawl 16 isreleased against the action of spring 18 as portion 31 of rod 25 bearsagainst the upper side of cam slot 24 in pawl 16 thereby raising thepawl in moving from the wide end of cam slot 24 rearwardly toward thenarrow end. Pedal 11 immediately upon release is swung back under pullof the parking brake cable C to its original position in abutment withbumper 37, and, of course, when the driver lets go of the handle 30, rod25 is returned Linder action of spring 28 to its initial positionreplacing pawl 16 under control of spring 18.

Referring to FIG. 3, this construction is the same as shown in FIGS. land 2 except that, in lieu of spring 18 actuating only the pawl 16, thisconstruction has a longer and heavier coiled tension spring 18'stretched directly between the pedal 11' and pawl 16', so that this onespring serves the double purpose of urging the pawl 16' towardengagement with the teeth 19' on ratchet 15', and also to hold the pedal11' normally in retracted position engaging lug 39 on plate 9', andaccordingly return it to that position after the pedal has beendepressed to apply the parking brake. In other words, there the pedal11' is free to return to its initial position instead of being tied upwith the ratchet as in the other form. The ratchet 15 in this form hasits forwardly reaching arm 14' connected by means of a clevis 21 withthe parking `brake cable C similarly as in the rst form, but, in thisform, a rubber bumper in the form of a sleeve 37' is mounted on a lug38' on plate 9' and cushions the return of the ratchet 1S' to its normalposition upon retraction of pawl 16' by means of pull-rod 25. The slot24 in pawl 16' is generally similar to the triangular slot 24 in pawl 16`but may be described as substantially L-shaped, the transverse frontend portion 40, which is of approximately the same length as the widefront end of triangular slot 24, being struck on an arc with pivot 17 asa center, so that the pawl 16 is free to oscillate the same as pawl 16so long as rod end 31' is in forward position. However, when rod 25 ispulled to the rear, the pawl 16' is retracted in the same way as pawl 16`by rod 25.

The operation of this form is he same as that of FIGS. 1 and 2 with theexceptions mentioned.

It is believed the foregoing description conveys a good understanding ofthe objects and advantages of my invention. The appended claims havebeen drawn to cover all legitimate modifications and adaptations.

I claim:

1. In combination in a foot-operated hand-released brake mechanism, afixed elongated supporting bracket having a front end and a rear end, abrake operating pedal pivotally mounted in said bracket in parallelreliationship thereto, a brake connected ratchet also movably mounted onsaid bracket in parallel relationship thereto and connected with saidpedal to move with it in the application of the brake, a at pawlpivotally mounted on and parallel to said bracket and engaging saidratchet to maintain the Abrake in applied position, spring meansnormally urging said pawl toward locking engagement with said ratchet,said pawl having an elongated cam [slot provide-d therein] surfaceprovided thereon in a lengthwise direction with respect to said bracket,said bracket having an elongated guide slot provided therein in acuteangular intersecting relationship to the [slot in] cam surface on saidpawl, manually operable rod Supported for endwisc reciprocation fore andaft relative to `sa-id bracket substantially parallel thereto and havinga cross-portion extending through the aforesaid [slots] slot so as to beguided for straight line movement endwise of the guide slot while movingendwise also of the cam [slot in] surface on said pawl to disengage saidpawl from said ratchet by cam action in endwise movement of said rod,[said cam slot having a widened end permitting oscillation of] said pawlbeing oscllatable freely relative to the Cross-portion of .raid rod onlyin one extreme position of the rod for locking engagement with saidratchet [freely relative to the cross-portion of said rod only in oneextreme position of the rod], and spring means normally urging saidmanually operable rod in one direction to locate its cross portion inthat end of the guide slot corresponding to the [widened end of said camslot] last mentioned extreme pos'lion of said rod.

2. A brake mechanism as set forth in claim 1 wherein the spring meansnormally urging the pawl toward locking engagement with the ratchet isalso connected with the `brake operating pedal tending normally toreturn it to a retnacted position.

3. A brake mechanism as set forth in claim 1 wherein the ratchet is ofsegmental form and said ratchet and pedal elements are pivotally mountedtogether on the same axis on said bracket and connected to swingtogether as a unit, said mechanism including a shock absorbing bumpermounted on said bracket and arranged for engagement only by one of saidratchet and pedal elements in its retracted position.

4. In combination in a foot-operated hand-released brake mechanism, afixed elongated supporting bracket having a front end and a rear end, abrake operating pedal pivotally mounted on said bracket in parallelrelationship thereto, a brake connected ratchet also movably mounted onsaid bracket in parallel relationship thereto and connected with saidpedal to move with it in the `application of the brake, a Hat pawlpivotally mounted on and parallel to said bracket and engaging saidratchet to maintain the brake in applied position, spring means normallyurging said pawl toward locking engagement with said ratchet, said pawlhaving `an elongated cam [slot] surface provided [therein] thereon in alength- Wise direction with respect to said bracket, said bracket having`an elongated guide slot provided therein in acute angular intersectingrelationship to `the [slot in] mm surface on said pawl, and a manuallyoperable rod supported for endwise reciprocation fore and aft relativeto said bracket substantially parallel thereto and having across-portion extending through the aforesaid [slots] slot `so las to beguided for straight line movement endwise of the guide slot while movingendwise also of the cam [slot in] surface on said pawl to disengage Saidpawl from said ratchet by cam action in endwise movement of said rod,[said cam slot having a widened end permitting oscillation of] said pawl[for locking engagement with said ratchet freely relative to thecross-portion of said rod] being ascii/arable freely relative to thecross-portion of said rod only in one extreme position of the rod, saidratchet being of segmental form and said ratchet and pedal elementsbeing pivotally mounted together on the same axis on said bracket andconnected to swing together in one direction in the application of thebrake, the pedal being free to pivot relative to said ratchet in theopposite direction to return to retracted position, the spring meansnormally urging the pawl toward locking engagement with the ratchetbeing also connected with said pedal to return it to retracted position.

5. A brake mechanism as set forth in claim 4 including separate bumpers-on said bracket for engagement by said ratchet and pedal respectivelyin retracted position.

6. A brake mechanism as set forth in claim 1 including a plate xed inspaced parallel relationship to said bracket so as to house said pawltherebetween, said plate having an elongated guide slot provided thereinin full register with the guide slot in said bracket, the crossportionof said rod being slidable at its opposite ends endwise of said giudeslots while slidable intermediate its ends endwise of the cam [slot in]surface on said pawl to disengage the latter from said ratchet.

7. A brake mechanism as set forth in claim 6 wherein said bracket andsaid plate `both have flanges delned thereon lengthwise of the guideslots therein for widened `bearing engagement of the cross-portion ofsaid rod in said slots and reduction of wear on said rod and guide slotsin the reciprocation of said rod.

8. A brake mechanism ats set forth in claim l wherein the team surfaceon the pawl is defined on one side of a cam slot provided in said pawl,said cam slot having a widened end permitting oscillation of said paw!for locking engagement with smid ratchet freely relative I0 thecross-portion of said rod only in said one extreme posilion 0-3 the rod.

9. A brake mechanism as set forth in claim 4 wherein the team surface onthe pawl is defined on one side of at cam slot provided in said pawl,said cam slot having at widened end permitting oscillation of said pawlfor lockini engagement with said' ratchet freely relative to thecross-portion of said rod only in said one extreme position of the rod.

References Cited The following references, cited by the Examiner, are ofrecord in the patented `ile of this patent or the original patent.

UNITED STATES PATENTS 1,117,278 11/1914 Thurber 74-538 2,694,945 11/1954Jandus 74-540 2,899,838 8/1939 Johnston 74-540 2,986,046 5/1961Vigmostad 711-540 FOREIGN PATENTS 820,907 8/1937 France. 104,886 8/1899Germany.

MILTON KAUFMAN, Primary Examiner.

